Fitbit just unveiled its two upcoming trackers, the Flex 2 and Charge 2, but there's more that the company is adding to its trackers' experience this week: Adventures.

Sitting inside the Challenges tab, there will be a new series of challenges to compete in, except these are personal ones that you can undertake at your own pace and with a lot more to gain than just bragging rights against your friends.

Last week, a fairly major update to Google Fit came with a fresh coat of paint for the interface and a few important feature enhancements. It now supports multiple goals with more options, weight tracking, new metrics, and quite a bit more. It wasn't a complete overhaul, but it certainly looks and feels like a whole new app. But that's not the whole story, there's actually quite a bit more in this update that hasn't emerged yet. A teardown reveals some other features that will either activate soon or turn up with the rollout of future updates. But before we get to that, there were actually a couple more things that popped up since the first post.

Active folks who fire up the latest version of the Fitbit app will see a new section tucked away in the sidebar: Challenges. Contained within is a way to take the fitness-minded company's Android experience and make it more social. Users now have the ability to challenge up to 10 people and compete with them in any of three contests.

Fitbit wearers can compete to see who can complete the most steps in a single day, over the weekend, or throughout an entire work week. Invitees have up to twenty-four hours to accept a challenge, and if they jump in after a competition starts, Fitbit will still count their data for the full length of time.